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This paper develops a flexible time-domain SAR imaging algorithm that is capable of accounting for somewhat arbitrary flight track geometries and platform orientations. The proposed technique casts SAR imaging as a maximum likelihood estimation problem where the ground reflectivities are taken as the parameters to be estimated. It is shown that conventional back projection is one of two steps required...
In this paper, we propose a new technique for image fusion in multi-view through-the-wall radar imaging system. As most existing image fusion methods for through-the-wall radar imaging only consider a global fusion operator, it is desirable to consider the differences between each pixel using a local operator. Here, we present a fuzzy logic-based method for pixel-wise image fusion. The performance...
Synthetic Aperture Radar (SAR) provides all day, all weather and long stand off range capability of imaging large areas of the Earth. Single pass Interferometric SAR (IFSAR) using a pair of vertically displaced phase centers can be effectively used to estimate height using SAR images corresponding to each phase center. In recent years, multiple input multiple output (MIMO) radar techniques have received...
Pleasingly parallel algorithms such as filtered back-projection have been documented to enjoy significant speedups when ported to run on a graphics processor instead of a standard CPU. Presented here is a two-dimensional SAR backprojection implementation for a single GPU using the NVIDIA CUDA framework. Given that input range projections may be too large to fit in graphics memory, our implementation...
In this paper a new segmentation method for SAR images is presented which requires applying edge detector such as Sobel, Robert, Prewitt, or canny. Then, use edge information in order to estimate the threshold values required for image segmentation. Segmenting SAR images with low contrast using the proposed method was very satisfactory and the obtained results are very promising.
This paper presents an overview of recent research progress in WSRS on theoretical modeling of the terrain surface for polarimetric scattering simulation and Mueller matrix solution, mono-static and bistatic SAR image simulation, new parameters for unsupervised surface classification based on de-orientation approach, DEM inversion, change detection from multi-temporal SAR images, and reconstructions...
In this work we present an eigenspace-like technique for the estimation of the unwrapped phase which is based on the model of the multi-baseline joint data group. The method is shown to work well even in the presence of the image coregistration misalignment and the steering vector mismatch, and has the ability to overcome the conflict associated with the computational complexity and the lack of the...
Three-dimensional imaging can provide more detail information of the target than two-dimensional image, which can be used to identify the target. Thus, it is very useful for detecting in enclosed structures or behind the obstacle. This paper mainly research on the three-dimensional through-the-wall human imaging and introduce an approximate method to calculate the propagation delay when electromagnetic...
Phase unwrapping is the key problem in building the digital elevation model (DEM) of a scene from interferometric synthetic aperture radar (SAR) system data. In this paper, we propose a method of phase unwrapping based on the model of the multibaseline joint data group. The method can not only adaptively coregister the SAR images, but also accurately provide the accurate estimation of the terrain...
Laser radar has enjoyed significant advances over the past decade. Novel sensor topologies, compact laser illuminators, and advanced signal processing have enabled the construction of low power, portable 2-D and 3-D laser vision systems. The applications of such systems range from surveillance, targeting, weapons guidance, and remote scene measurement, to target identification and atmospheric characterization...
Through the wall imaging (TWI) is a difficult but important task for both law enforcement and military missions. Getting information on both the internal features of a structure and the location of people inside is playing an important role in many fields such as anti-terrorism, search and rescue hostage, and barricade situations. Up to now, many researchers have developed diverse experimental systems,...
This paper briefly discusses some of the RF heterodyne imaging applications and instruments that are being developed and deployed for the THz frequency regime. After more than three decades of academic research the THz equivalent of the IR camera is still confined to proposals. However, as the component technology matures and new instruments emerge, interest in applications has followed. Some of the...
Synthetic aperture radar (SAR) as a method for ground imaging by using a single antenna or a sensor array has widely found attraction for remote sensing applications and reconnaissance tasks. Independent of the particular sensor but inherent to the SAR processing, moving objects in the observed scene will be imaged at wrong positions and can appear in a smeared fashion. To avoid these disturbing artifacts...
Cross-correlation based image subtraction for detection of targets within an urban structure from synthetic aperture radar images is presented. In surveillance operations requiring re-imaging of the same scene, small displacements in array element locations may cause large phase and amplitude offsets. Subsequently, clutter will not cancel out, but will rather persist when subtracting two images, one...
Through-the-wall radar imaging attempts to image complex scenes within enclosed structures. While most of the high-resolution imaging techniques assume point targets, indoor imaging requires dealing with single or multiple walls which are extended targets in nature and violate the point-target assumption. In order to provide high quality imaging, we need to consider point targets and extended targets...
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